Automatic Teller Machines (ATMs), which were introduced in order to save labor and ease congestion at the counter at banks, have become widely used as they have increased in numbers and improved in level of service. Typically, an ATM is connected on-line, in some cases through an intermediary communicator known as a message broker, to a host computer. The ATM sends and receives electronic messages to and from the host computer to cause the host computer to perform banking transactions specified by users, such as deposits, withdrawals, bookkeeping, and finds transfer, and to perform actions such as dispensing cash and displaying or printing the results of transactions.
ATMs do not respond properly to commands provided by users if they cannot receive messages sent from the host computer due to failure in the host computer. Therefore, if failure occurs in the host computer, the failure must be immediately detected and fixed, or other countermeasures must be taken.
A technology for monitoring the operating status of a computer located in a remote location and connected over a communication line is disclosed in Published Unexamined Patent Application No. 2001-318840. In that technology, an operation-surveillance computer in a computer network sends electronic mail to a monitored computer for determining the monitored computer's operating status based on whether the surveillance computer receives an electronic mail reply from the monitored computer within a predetermined period of time.
Published Unexamined Patent Application No. 8-314762 discloses a technology in which a monitored computer sends a message to a surveillance computer at regular intervals and, if the message does not arrive within a predetermined period of time, the surveillance computer determines that an error has occurred and activates an alarm device.
Requests for banking transactions tend to concentrate in a certain period of time. A failure that occurs during a busy period may severely affect operations at the banking institution. The technologies described in Published Unexamined Laid-Open Patent Applications No. 2001-318840 and No. 8-314762 determine that failure has occurred in a computer system if information such as mail or a message does not arrive at the estimated time at which it should otherwise arrive. These technologies do not enable prediction of failure. Therefore, although the failure in a computer system of a banking institution can be detected by using these technologies, it is difficult to prevent impairment of operations in the banking institution due to the failure.
An object of the present invention is to provide a computer system that can predict the failure.